In a preparation of a semi-conductor device, fine patterns are formed by photolithography processes using photoresist to increase processing speed and capability. In the process using photoresist, to form fine patterns and a desired circuit, the effect of light on the patterns to be formed should be minimized by blocking the reflected or refracted light from the bottom. An anti-reflective coating layer (bottom anti-reflective coatings: BARCs) blocks the reflected or refracted light from the bottom, and thus the anti-reflective coating layer is indispensable to the photolithography process as the circuit is fine-sized.
The anti-reflective coating layer should be not dissolved in or mixed with solvent for photoresist which is coated on the anti-reflective coating layer. Therefore, the anti-reflective coating layer still remains after photoresist patterns are formed. An etching process of anti-reflective coating layer must be carried out first before etching a substrate on which the desired circuit is to be formed. The thickness of photoresist layer is getting thinner for minimizing circuit constantly. So, the thickness of remained anti-reflective coating layer makes the etching process of the substrate difficult. Moreover, after etching the anti-reflective coating layer, the etching process of substrate comes to a difficult state to be carried out. If an anti-reflective coating layer which can be patterned with photoresist at the same time is applied, the etching process of the anti-reflective coating layer can be eliminated, so that in the etching process of substrate, the difficulty of etching is reduced. Therefore, the above mentioned process is more advantageous in view of the process and cost over the process using a conventional anti-reflective coating layer. This trend is shown in U.S. Pat. No. 6,156,479 and Japanese Patent Publication No. 9-78031, but the disclosures have disadvantages that the formation of fine patterns and the control of reaction are difficult.